1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_SIGNAL_H
3 #define _LINUX_SIGNAL_H
4
5 #include <linux/bug.h>
6 #include <linux/signal_types.h>
7 #include <linux/string.h>
8
9 struct task_struct;
10
11 /* for sysctl */
12 extern int print_fatal_signals;
13
copy_siginfo(struct siginfo * to,const struct siginfo * from)14 static inline void copy_siginfo(struct siginfo *to, const struct siginfo *from)
15 {
16 memcpy(to, from, sizeof(*to));
17 }
18
clear_siginfo(struct siginfo * info)19 static inline void clear_siginfo(struct siginfo *info)
20 {
21 memset(info, 0, sizeof(*info));
22 }
23
24 int copy_siginfo_to_user(struct siginfo __user *to, const struct siginfo *from);
25
26 enum siginfo_layout {
27 SIL_KILL,
28 SIL_TIMER,
29 SIL_POLL,
30 SIL_FAULT,
31 SIL_FAULT_MCEERR,
32 SIL_FAULT_BNDERR,
33 SIL_FAULT_PKUERR,
34 SIL_CHLD,
35 SIL_RT,
36 SIL_SYS,
37 };
38
39 enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
40
41 /*
42 * Define some primitives to manipulate sigset_t.
43 */
44
45 #ifndef __HAVE_ARCH_SIG_BITOPS
46 #include <linux/bitops.h>
47
48 /* We don't use <linux/bitops.h> for these because there is no need to
49 be atomic. */
sigaddset(sigset_t * set,int _sig)50 static inline void sigaddset(sigset_t *set, int _sig)
51 {
52 unsigned long sig = _sig - 1;
53 if (_NSIG_WORDS == 1)
54 set->sig[0] |= 1UL << sig;
55 else
56 set->sig[sig / _NSIG_BPW] |= 1UL << (sig % _NSIG_BPW);
57 }
58
sigdelset(sigset_t * set,int _sig)59 static inline void sigdelset(sigset_t *set, int _sig)
60 {
61 unsigned long sig = _sig - 1;
62 if (_NSIG_WORDS == 1)
63 set->sig[0] &= ~(1UL << sig);
64 else
65 set->sig[sig / _NSIG_BPW] &= ~(1UL << (sig % _NSIG_BPW));
66 }
67
sigismember(sigset_t * set,int _sig)68 static inline int sigismember(sigset_t *set, int _sig)
69 {
70 unsigned long sig = _sig - 1;
71 if (_NSIG_WORDS == 1)
72 return 1 & (set->sig[0] >> sig);
73 else
74 return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
75 }
76
77 #endif /* __HAVE_ARCH_SIG_BITOPS */
78
sigisemptyset(sigset_t * set)79 static inline int sigisemptyset(sigset_t *set)
80 {
81 switch (_NSIG_WORDS) {
82 case 4:
83 return (set->sig[3] | set->sig[2] |
84 set->sig[1] | set->sig[0]) == 0;
85 case 2:
86 return (set->sig[1] | set->sig[0]) == 0;
87 case 1:
88 return set->sig[0] == 0;
89 default:
90 BUILD_BUG();
91 return 0;
92 }
93 }
94
sigequalsets(const sigset_t * set1,const sigset_t * set2)95 static inline int sigequalsets(const sigset_t *set1, const sigset_t *set2)
96 {
97 switch (_NSIG_WORDS) {
98 case 4:
99 return (set1->sig[3] == set2->sig[3]) &&
100 (set1->sig[2] == set2->sig[2]) &&
101 (set1->sig[1] == set2->sig[1]) &&
102 (set1->sig[0] == set2->sig[0]);
103 case 2:
104 return (set1->sig[1] == set2->sig[1]) &&
105 (set1->sig[0] == set2->sig[0]);
106 case 1:
107 return set1->sig[0] == set2->sig[0];
108 }
109 return 0;
110 }
111
112 #define sigmask(sig) (1UL << ((sig) - 1))
113
114 #ifndef __HAVE_ARCH_SIG_SETOPS
115 #include <linux/string.h>
116
117 #define _SIG_SET_BINOP(name, op) \
118 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
119 { \
120 unsigned long a0, a1, a2, a3, b0, b1, b2, b3; \
121 \
122 switch (_NSIG_WORDS) { \
123 case 4: \
124 a3 = a->sig[3]; a2 = a->sig[2]; \
125 b3 = b->sig[3]; b2 = b->sig[2]; \
126 r->sig[3] = op(a3, b3); \
127 r->sig[2] = op(a2, b2); \
128 case 2: \
129 a1 = a->sig[1]; b1 = b->sig[1]; \
130 r->sig[1] = op(a1, b1); \
131 case 1: \
132 a0 = a->sig[0]; b0 = b->sig[0]; \
133 r->sig[0] = op(a0, b0); \
134 break; \
135 default: \
136 BUILD_BUG(); \
137 } \
138 }
139
140 #define _sig_or(x,y) ((x) | (y))
_SIG_SET_BINOP(sigorsets,_sig_or)141 _SIG_SET_BINOP(sigorsets, _sig_or)
142
143 #define _sig_and(x,y) ((x) & (y))
144 _SIG_SET_BINOP(sigandsets, _sig_and)
145
146 #define _sig_andn(x,y) ((x) & ~(y))
147 _SIG_SET_BINOP(sigandnsets, _sig_andn)
148
149 #undef _SIG_SET_BINOP
150 #undef _sig_or
151 #undef _sig_and
152 #undef _sig_andn
153
154 #define _SIG_SET_OP(name, op) \
155 static inline void name(sigset_t *set) \
156 { \
157 switch (_NSIG_WORDS) { \
158 case 4: set->sig[3] = op(set->sig[3]); \
159 set->sig[2] = op(set->sig[2]); \
160 case 2: set->sig[1] = op(set->sig[1]); \
161 case 1: set->sig[0] = op(set->sig[0]); \
162 break; \
163 default: \
164 BUILD_BUG(); \
165 } \
166 }
167
168 #define _sig_not(x) (~(x))
169 _SIG_SET_OP(signotset, _sig_not)
170
171 #undef _SIG_SET_OP
172 #undef _sig_not
173
174 static inline void sigemptyset(sigset_t *set)
175 {
176 switch (_NSIG_WORDS) {
177 default:
178 memset(set, 0, sizeof(sigset_t));
179 break;
180 case 2: set->sig[1] = 0;
181 case 1: set->sig[0] = 0;
182 break;
183 }
184 }
185
sigfillset(sigset_t * set)186 static inline void sigfillset(sigset_t *set)
187 {
188 switch (_NSIG_WORDS) {
189 default:
190 memset(set, -1, sizeof(sigset_t));
191 break;
192 case 2: set->sig[1] = -1;
193 case 1: set->sig[0] = -1;
194 break;
195 }
196 }
197
198 /* Some extensions for manipulating the low 32 signals in particular. */
199
sigaddsetmask(sigset_t * set,unsigned long mask)200 static inline void sigaddsetmask(sigset_t *set, unsigned long mask)
201 {
202 set->sig[0] |= mask;
203 }
204
sigdelsetmask(sigset_t * set,unsigned long mask)205 static inline void sigdelsetmask(sigset_t *set, unsigned long mask)
206 {
207 set->sig[0] &= ~mask;
208 }
209
sigtestsetmask(sigset_t * set,unsigned long mask)210 static inline int sigtestsetmask(sigset_t *set, unsigned long mask)
211 {
212 return (set->sig[0] & mask) != 0;
213 }
214
siginitset(sigset_t * set,unsigned long mask)215 static inline void siginitset(sigset_t *set, unsigned long mask)
216 {
217 set->sig[0] = mask;
218 switch (_NSIG_WORDS) {
219 default:
220 memset(&set->sig[1], 0, sizeof(long)*(_NSIG_WORDS-1));
221 break;
222 case 2: set->sig[1] = 0;
223 case 1: ;
224 }
225 }
226
siginitsetinv(sigset_t * set,unsigned long mask)227 static inline void siginitsetinv(sigset_t *set, unsigned long mask)
228 {
229 set->sig[0] = ~mask;
230 switch (_NSIG_WORDS) {
231 default:
232 memset(&set->sig[1], -1, sizeof(long)*(_NSIG_WORDS-1));
233 break;
234 case 2: set->sig[1] = -1;
235 case 1: ;
236 }
237 }
238
239 #endif /* __HAVE_ARCH_SIG_SETOPS */
240
init_sigpending(struct sigpending * sig)241 static inline void init_sigpending(struct sigpending *sig)
242 {
243 sigemptyset(&sig->signal);
244 INIT_LIST_HEAD(&sig->list);
245 }
246
247 extern void flush_sigqueue(struct sigpending *queue);
248
249 /* Test if 'sig' is valid signal. Use this instead of testing _NSIG directly */
valid_signal(unsigned long sig)250 static inline int valid_signal(unsigned long sig)
251 {
252 return sig <= _NSIG ? 1 : 0;
253 }
254
255 struct timespec;
256 struct pt_regs;
257 enum pid_type;
258
259 extern int next_signal(struct sigpending *pending, sigset_t *mask);
260 extern int do_send_sig_info(int sig, struct siginfo *info,
261 struct task_struct *p, enum pid_type type);
262 extern int group_send_sig_info(int sig, struct siginfo *info,
263 struct task_struct *p, enum pid_type type);
264 extern int __group_send_sig_info(int, struct siginfo *, struct task_struct *);
265 extern int sigprocmask(int, sigset_t *, sigset_t *);
266 extern void set_current_blocked(sigset_t *);
267 extern void __set_current_blocked(const sigset_t *);
268 extern int show_unhandled_signals;
269
270 extern bool get_signal(struct ksignal *ksig);
271 extern void signal_setup_done(int failed, struct ksignal *ksig, int stepping);
272 extern void exit_signals(struct task_struct *tsk);
273 extern void kernel_sigaction(int, __sighandler_t);
274
275 #define SIG_KTHREAD ((__force __sighandler_t)2)
276 #define SIG_KTHREAD_KERNEL ((__force __sighandler_t)3)
277
allow_signal(int sig)278 static inline void allow_signal(int sig)
279 {
280 /*
281 * Kernel threads handle their own signals. Let the signal code
282 * know it'll be handled, so that they don't get converted to
283 * SIGKILL or just silently dropped.
284 */
285 kernel_sigaction(sig, SIG_KTHREAD);
286 }
287
allow_kernel_signal(int sig)288 static inline void allow_kernel_signal(int sig)
289 {
290 /*
291 * Kernel threads handle their own signals. Let the signal code
292 * know signals sent by the kernel will be handled, so that they
293 * don't get silently dropped.
294 */
295 kernel_sigaction(sig, SIG_KTHREAD_KERNEL);
296 }
297
disallow_signal(int sig)298 static inline void disallow_signal(int sig)
299 {
300 kernel_sigaction(sig, SIG_IGN);
301 }
302
303 extern struct kmem_cache *sighand_cachep;
304
305 extern bool unhandled_signal(struct task_struct *tsk, int sig);
306
307 /*
308 * In POSIX a signal is sent either to a specific thread (Linux task)
309 * or to the process as a whole (Linux thread group). How the signal
310 * is sent determines whether it's to one thread or the whole group,
311 * which determines which signal mask(s) are involved in blocking it
312 * from being delivered until later. When the signal is delivered,
313 * either it's caught or ignored by a user handler or it has a default
314 * effect that applies to the whole thread group (POSIX process).
315 *
316 * The possible effects an unblocked signal set to SIG_DFL can have are:
317 * ignore - Nothing Happens
318 * terminate - kill the process, i.e. all threads in the group,
319 * similar to exit_group. The group leader (only) reports
320 * WIFSIGNALED status to its parent.
321 * coredump - write a core dump file describing all threads using
322 * the same mm and then kill all those threads
323 * stop - stop all the threads in the group, i.e. TASK_STOPPED state
324 *
325 * SIGKILL and SIGSTOP cannot be caught, blocked, or ignored.
326 * Other signals when not blocked and set to SIG_DFL behaves as follows.
327 * The job control signals also have other special effects.
328 *
329 * +--------------------+------------------+
330 * | POSIX signal | default action |
331 * +--------------------+------------------+
332 * | SIGHUP | terminate |
333 * | SIGINT | terminate |
334 * | SIGQUIT | coredump |
335 * | SIGILL | coredump |
336 * | SIGTRAP | coredump |
337 * | SIGABRT/SIGIOT | coredump |
338 * | SIGBUS | coredump |
339 * | SIGFPE | coredump |
340 * | SIGKILL | terminate(+) |
341 * | SIGUSR1 | terminate |
342 * | SIGSEGV | coredump |
343 * | SIGUSR2 | terminate |
344 * | SIGPIPE | terminate |
345 * | SIGALRM | terminate |
346 * | SIGTERM | terminate |
347 * | SIGCHLD | ignore |
348 * | SIGCONT | ignore(*) |
349 * | SIGSTOP | stop(*)(+) |
350 * | SIGTSTP | stop(*) |
351 * | SIGTTIN | stop(*) |
352 * | SIGTTOU | stop(*) |
353 * | SIGURG | ignore |
354 * | SIGXCPU | coredump |
355 * | SIGXFSZ | coredump |
356 * | SIGVTALRM | terminate |
357 * | SIGPROF | terminate |
358 * | SIGPOLL/SIGIO | terminate |
359 * | SIGSYS/SIGUNUSED | coredump |
360 * | SIGSTKFLT | terminate |
361 * | SIGWINCH | ignore |
362 * | SIGPWR | terminate |
363 * | SIGRTMIN-SIGRTMAX | terminate |
364 * +--------------------+------------------+
365 * | non-POSIX signal | default action |
366 * +--------------------+------------------+
367 * | SIGEMT | coredump |
368 * +--------------------+------------------+
369 *
370 * (+) For SIGKILL and SIGSTOP the action is "always", not just "default".
371 * (*) Special job control effects:
372 * When SIGCONT is sent, it resumes the process (all threads in the group)
373 * from TASK_STOPPED state and also clears any pending/queued stop signals
374 * (any of those marked with "stop(*)"). This happens regardless of blocking,
375 * catching, or ignoring SIGCONT. When any stop signal is sent, it clears
376 * any pending/queued SIGCONT signals; this happens regardless of blocking,
377 * catching, or ignored the stop signal, though (except for SIGSTOP) the
378 * default action of stopping the process may happen later or never.
379 */
380
381 #ifdef SIGEMT
382 #define SIGEMT_MASK rt_sigmask(SIGEMT)
383 #else
384 #define SIGEMT_MASK 0
385 #endif
386
387 #if SIGRTMIN > BITS_PER_LONG
388 #define rt_sigmask(sig) (1ULL << ((sig)-1))
389 #else
390 #define rt_sigmask(sig) sigmask(sig)
391 #endif
392
393 #define siginmask(sig, mask) \
394 ((sig) < SIGRTMIN && (rt_sigmask(sig) & (mask)))
395
396 #define SIG_KERNEL_ONLY_MASK (\
397 rt_sigmask(SIGKILL) | rt_sigmask(SIGSTOP))
398
399 #define SIG_KERNEL_STOP_MASK (\
400 rt_sigmask(SIGSTOP) | rt_sigmask(SIGTSTP) | \
401 rt_sigmask(SIGTTIN) | rt_sigmask(SIGTTOU) )
402
403 #define SIG_KERNEL_COREDUMP_MASK (\
404 rt_sigmask(SIGQUIT) | rt_sigmask(SIGILL) | \
405 rt_sigmask(SIGTRAP) | rt_sigmask(SIGABRT) | \
406 rt_sigmask(SIGFPE) | rt_sigmask(SIGSEGV) | \
407 rt_sigmask(SIGBUS) | rt_sigmask(SIGSYS) | \
408 rt_sigmask(SIGXCPU) | rt_sigmask(SIGXFSZ) | \
409 SIGEMT_MASK )
410
411 #define SIG_KERNEL_IGNORE_MASK (\
412 rt_sigmask(SIGCONT) | rt_sigmask(SIGCHLD) | \
413 rt_sigmask(SIGWINCH) | rt_sigmask(SIGURG) )
414
415 #define SIG_SPECIFIC_SICODES_MASK (\
416 rt_sigmask(SIGILL) | rt_sigmask(SIGFPE) | \
417 rt_sigmask(SIGSEGV) | rt_sigmask(SIGBUS) | \
418 rt_sigmask(SIGTRAP) | rt_sigmask(SIGCHLD) | \
419 rt_sigmask(SIGPOLL) | rt_sigmask(SIGSYS) | \
420 SIGEMT_MASK )
421
422 #define sig_kernel_only(sig) siginmask(sig, SIG_KERNEL_ONLY_MASK)
423 #define sig_kernel_coredump(sig) siginmask(sig, SIG_KERNEL_COREDUMP_MASK)
424 #define sig_kernel_ignore(sig) siginmask(sig, SIG_KERNEL_IGNORE_MASK)
425 #define sig_kernel_stop(sig) siginmask(sig, SIG_KERNEL_STOP_MASK)
426 #define sig_specific_sicodes(sig) siginmask(sig, SIG_SPECIFIC_SICODES_MASK)
427
428 #define sig_fatal(t, signr) \
429 (!siginmask(signr, SIG_KERNEL_IGNORE_MASK|SIG_KERNEL_STOP_MASK) && \
430 (t)->sighand->action[(signr)-1].sa.sa_handler == SIG_DFL)
431
432 void signals_init(void);
433
434 int restore_altstack(const stack_t __user *);
435 int __save_altstack(stack_t __user *, unsigned long);
436
437 #define save_altstack_ex(uss, sp) do { \
438 stack_t __user *__uss = uss; \
439 struct task_struct *t = current; \
440 put_user_ex((void __user *)t->sas_ss_sp, &__uss->ss_sp); \
441 put_user_ex(t->sas_ss_flags, &__uss->ss_flags); \
442 put_user_ex(t->sas_ss_size, &__uss->ss_size); \
443 if (t->sas_ss_flags & SS_AUTODISARM) \
444 sas_ss_reset(t); \
445 } while (0);
446
447 #ifdef CONFIG_PROC_FS
448 struct seq_file;
449 extern void render_sigset_t(struct seq_file *, const char *, sigset_t *);
450 #endif
451
452 #endif /* _LINUX_SIGNAL_H */
453